Hi Artie,
Cool game, sorry I missed the first 3 photo's! I think it is a matter of preference here. I would choose C as a more intimate/contact with the viewer shot because of the HA being slightly tilted towards the viewer compared to the body angle which points towards the viewer but also downwards. For a behavior kind of shot I would go for D. In this one the bird seems more focussed on the prey item and oblivious to the photographer (caused by the head and body angle being in the same plane and pointed towards the viewer but also down towards the prey item) which makes it more of a bahavioral kind of shot IMHO. So what I am getting at is that in my opinion it depends on what kind of a HA you want, one that is perfect technically or one that creates more of a behavioral kind of shot. Just my 2 cents.
Thanks for starting this one up.
Cheers,
Krijn